A histogram is used to show the frequency of data, where the length of the bar represents the frequency.
<em>50 students drank the recommended amount of water.</em>
The recommended amount is given as:

See attachment for histogram.
From the histogram, we have the following observations
- <em>The lengths of all bars of the histogram are less than 48, except one.</em>
- <em>The length of the bar above 48 is 50.</em>
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This means that: 50 students drank the recommended amount of water.
<em>Hence, the number of students is 50</em>
Read more about histograms at
brainly.com/question/24577156